fix(ci): simplify test runner to plain bun test by fixing mock.module() leakage

- Add afterAll(() => { mock.restore() }) to 52 test files missing cleanup
- Rewrite create-tool-guard-hooks.test.ts to use spyOn instead of barrel mock
- Fix skill-mcp-manager OAuth tests with missing mockTokens/mockLogin definitions
- Fix start-work hook: show worktree active block on resume with existing worktree_path
- Extract createWorktreeActiveBlock to worktree-block.ts to avoid circular import
- Replace 80-line isolated test runner CI config with single `bun test` command

src/hooks/compaction-context-injector/index.test.ts

@@ -1,4 +1,4 @@
-import { describe, expect, it, mock } from "bun:test"
+import { afterAll, describe, expect, it, mock } from "bun:test"
 
 mock.module("../../shared/system-directive", () => ({
   createSystemDirective: (type: string) => `[DIRECTIVE:${type}]`,
@@ -14,6 +14,10 @@ mock.module("../../shared/system-directive", () => ({
   },
 }))
 
+afterAll(() => {
+  mock.restore()
+})
+
 import { createCompactionContextInjector } from "./index"
 import { TaskHistory } from "../../features/background-agent/task-history"